The update to iOS 12.3 has arrived and with it also the update to tvOS 12.3 with The great novelty of bringing the new app "Apple TV", but in Spain we will still have to wait to enjoy it in all its splendor.
Although we already have the new app "Apple TV" on our Apple TV, the truth is that there is not much difference with the app «Movies», so the function of a direct access in our command to this new app may be of little use in our day-to-day life.
As of tvOS 12.3 the start button of the Siri Remote (the button with a screen icon) will take us to the «Next» menu of the «Apple TV» app. As we said, reserving a button to go directly to this new app, today, does not make much sense, since the content and functions that would be interesting have not yet arrived, being, practically, another «Movies» app.
If we want to recover, at least until the expected functions of Apple TV (and the original Apple content) arrive, we can do them from the Apple TV Settings. In the "Controls and devices" menu, we can toggle the "Home button" between "Apple TV app" and "Home screen". Thus, with a single touch to the home button we will return to the home screen as we are used to.
If we decide not to change this new setting, a press on the start button (or, as it is called now, the "Apple TV App / Start" button) will take us to the "Apple TV" app and two presses will take us to the home screen.
In both configurations, holding down the start button or «Apple TV App / Home» will give us the possibility to send the Apple TV to sleep (and, if we have it configured on our television, turn off the television at the same time).